Preparation method for external pressure tubular membrane

Abstract

The invention belongs to the field of manufacture of separating membranes, and relates to a preparation method for an external pressure tubular membrane. A prepared porous membrane can be used for fields of environmental protection, water treatment, membrane separation and the like. The preparation method includes steps that a strip-shaped flat membrane is continuously wound on a center shaft in a certain winding angle, during winding, a membrane separating layer is outward, two sides of a membrane strap are mutually overlapped, the overlapped portions are integrally adhered or ultrasonically welded, then a prepared membrane tube is separated from the center shaft, and accordingly the external pressure tubular membrane is obtained. A combination of the separating layer of the external pressure tubular membrane and non-woven fabrics is firmer than a combination of the separating layer of the external pressure tubular membrane and braided tube textile fibers, so that the external pressure tubular membrane is not easy to shed; the mechanical strength of the external pressure tubular membrane is better than that a braided tube reinforcing membrane, and accordingly the external pressure tubular membranes are not easy to fall laterally or twined mutually; and membrane manufacturing efficiency is high, the external pressure tubular membrane is suitable for batch production and can be recoiled. The external pressure tubular membrane comprises a microfiltration membrane or an ultrafiltration membrane or a nanofiltration membrane, and is particularly suitable for membrane bioreactors and a recycled water process.

Description

Technical field [0001] The invention belongs to the field of separation membrane manufacturing, and relates to a method for preparing an external pressure tubular porous membrane (including nanofiltration membrane, microfiltration membrane and ultrafiltration membrane) by using a flat membrane through bonding and welding. The prepared porous membrane can be used in the fields of environmental protection, water treatment, membrane separation and the like. Background technique [0002] Polymer porous membranes (including nanofiltration membranes, microfiltration membranes and ultrafiltration membranes) have a variety of preparation methods, the most common of which are the non-solvent-induced phase separation (NIPS, DIPS) method, also known as the "immersion precipitation method" (IP method), tensile method and thermally induced phase separation (TIPS). The forms of polymer porous membranes are flat plate, hollow fiber, capillary and tubular. As described in US Patent (75174...

AI Technical Summary

Problems solved by technology

[0010] The present invention aims to solve the technical problems of the braided tube reinforced capillary membrane in the known technology that the film is easy to fall off and has low hardness, and the technical problem that the plate and frame membrane module cannot recoil and the cost is high. The prefabricated support tube is then coated to manufacture the tubular type Complicated technical issues in the membrane production process, revealing a method of manufacturing external pressure tubular membranes by winding strips of flat membranes or welding them

Images